Patients will be recruited from the GI oncology clinic of the North Carolina Cancer Hospital. After obtaining informed consent, patients will be entered into Part 1 of the study until the MTD has been defined. During study Part 1, patients will be given a 4 day run-in of curcumin prior to irinotecan dosing. The planned dose levels of curcumin will be 1, 2, 3, and 4 grams per day. Irinotecan will be dosed at 200 mg/m2 IV on days 1 and 15.46 Additional antineoplastic agents will not be allowed during the trial. Two patients will be enrolled at each dose level until a DLT occurs, beginning with the lowest dose level and increasing the level only after 2 patients have successfully completed a full irinotecan cycle at that dose level.